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View Full Version : "ActualStars.lwo" -- what's the story?



jeric_synergy
12-17-2017, 06:12 PM
The LWG content folders contain (or used to) a standard object, "ActualStars.lwo", with 6 Surfaces of varying magnitudes.

What's the story with this object? From 0/0/0 does it depict some specific set of stars???

MonroePoteet
12-17-2017, 09:48 PM
Doubt it. Setting the Camera to (0,0,0), setting rotation to (0,-90,0) (i.e. straight up) and setting the focal length down quite a bit (6mm), a high-def render looks nothing even close to the northern night sky. No recognizable constellations, no significant difference in brightness as there is with real stars, etc.

Certainly the object itself doesn't have any depth, as actual stars would have. It's a fixed-radius sphere (100km radius) populated with 1-point polygons. Even if it was scaled down radically, there would be differences in the distance of stars from the origin (i.e. Earth).

mTp

jeric_synergy
12-18-2017, 12:01 AM
Your second point is only important if parallax is percievable , no? So I don't have any problem with the stars located on a spherical shell, as they appear to be in RL without advanced instruments.

AND they are Surfaced with 6 magnitudes, so somebody was trying something.

stiff paper
12-18-2017, 03:15 AM
I'm pretty sure I remember ActualStars appearing in the LW 5.0 content. I'm also fairly sure somebody made it with... ooh... what was it called? RandPricks? It's the same method as how the stars were done for Babylon 5.

It's not real star positions as far as I know.

Chrusion
12-20-2017, 09:00 PM
To make a REAL star point cloud from publicly available star catalog position, magnitude, and color data, I created an Lscript called "Real 3D Star Cloud Generator," many years ago. It still works in the newer versions of Modeler.

You can get it and a 2 miilion star catalog data here:

Lscript (https://www.dropbox.com/s/cfmuftpol53es1a/Real3dStarGen.ls?dl=1)

2 million star CSV (87 mb) (https://www.dropbox.com/s/cc7pf9c1psvwqd2/Tycho2_2057K%2BGaiaPlx_Mag5%2B.csv?dl=1)

Open the CSV in spreadsheet to identify the header column numbers, then set them in the script.

Alternatively, here's the already created LWO (117 mb):

2.4 million star point cloud LWO (https://www.dropbox.com/s/b2eh8gbc3upfby7/RealStars_2057K_Gaia%2B370K_Tycho2_App.lwo?dl=1)

With this many stars, you can render a 360 equirectangular image and see the Milkyway and central bulge.
Sample Image (https://www.dropbox.com/s/ry6wi5jfewtydoh/Stars_2057K_Gaia+370K_Tycho2_10000.jpg?dl=1)

shrox
12-20-2017, 09:39 PM
To make a REAL star point cloud from publicly available star catalog position, magnitude, and color data, I created an Lscript called "Real 3D Star Cloud Generator," many years ago. It still works in the newer versions of Modeler.

You can get it and a 2 miilion star catalog data here:

Lscript (https://www.dropbox.com/s/cfmuftpol53es1a/Real3dStarGen.ls?dl=1)

2 million star CSV (87 mb) (https://www.dropbox.com/s/cc7pf9c1psvwqd2/Tycho2_2057K%2BGaiaPlx_Mag5%2B.csv?dl=1)

Open the CSV in spreadsheet to identify the header column numbers, then set them in the script.

Alternatively, here's the already created LWO (117 mb):

2.4 million star point cloud LWO (https://www.dropbox.com/s/b2eh8gbc3upfby7/RealStars_2057K_Gaia%2B370K_Tycho2_App.lwo?dl=1)

With this many stars, you can render a 360 equirectangular image and see the Milkyway and central bulge.
Sample Image (https://www.dropbox.com/s/ry6wi5jfewtydoh/Stars_2057K_Gaia+370K_Tycho2_10000.jpg?dl=1)

Well, this is sweet!

jeric_synergy
12-21-2017, 12:11 AM
Wow. Will have to look when I'm not asleep.

ElusiveElephant
12-21-2017, 07:35 AM
I'm pretty sure I remember ActualStars appearing in the LW 5.0 content. I'm also fairly sure somebody made it with... ooh... what was it called? RandPricks? It's the same method as how the stars were done for Babylon 5.

It's not real star positions as far as I know.

Oh, wow, thanks for clearing that up.

All this time I thought that plugin was for generating LW forum trolls! ;)








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Any copyright infringement herein is with approval from the originators :)

Bill Carey
12-21-2017, 08:14 AM
To make a REAL star point cloud from publicly available star catalog position, magnitude, and color data, I created an Lscript called "Real 3D Star Cloud Generator," many years ago. It still works in the newer versions of Modeler.

You can get it and a 2 miilion star catalog data here:

Lscript (https://www.dropbox.com/s/cfmuftpol53es1a/Real3dStarGen.ls?dl=1)

2 million star CSV (87 mb) (https://www.dropbox.com/s/cc7pf9c1psvwqd2/Tycho2_2057K%2BGaiaPlx_Mag5%2B.csv?dl=1)

Open the CSV in spreadsheet to identify the header column numbers, then set them in the script.

Alternatively, here's the already created LWO (117 mb):

2.4 million star point cloud LWO (https://www.dropbox.com/s/b2eh8gbc3upfby7/RealStars_2057K_Gaia%2B370K_Tycho2_App.lwo?dl=1)

With this many stars, you can render a 360 equirectangular image and see the Milkyway and central bulge.
Sample Image (https://www.dropbox.com/s/ry6wi5jfewtydoh/Stars_2057K_Gaia+370K_Tycho2_10000.jpg?dl=1)

Fantastic, thank you!

fishhead
12-21-2017, 08:25 AM
To make a REAL star point cloud from publicly available star catalog position, magnitude, and color data, I created an Lscript called "Real 3D Star Cloud Generator," many years ago. It still works in the newer versions of Modeler.

You can get it and a 2 miilion star catalog data here:

Lscript (https://www.dropbox.com/s/cfmuftpol53es1a/Real3dStarGen.ls?dl=1)

2 million star CSV (87 mb) (https://www.dropbox.com/s/cc7pf9c1psvwqd2/Tycho2_2057K%2BGaiaPlx_Mag5%2B.csv?dl=1)

Open the CSV in spreadsheet to identify the header column numbers, then set them in the script.

Alternatively, here's the already created LWO (117 mb):

2.4 million star point cloud LWO (https://www.dropbox.com/s/b2eh8gbc3upfby7/RealStars_2057K_Gaia%2B370K_Tycho2_App.lwo?dl=1)

With this many stars, you can render a 360 equirectangular image and see the Milkyway and central bulge.
Sample Image (https://www.dropbox.com/s/ry6wi5jfewtydoh/Stars_2057K_Gaia+370K_Tycho2_10000.jpg?dl=1)

Wow! Amazing! Thank you!!